Display device

ABSTRACT

In an IPS-mode liquid crystal display device, the area of a terminal portion is decreased. A liquid crystal display device includes a TFT substrate and a counter substrate attached to the TFT substrate with a sealing material, and includes a display region and a terminal portion formed on the TFT substrate. A shielding transparent conductive film is formed on the outer side of the counter substrate. On the terminal portion, an earth pad formed with a transparent conductive film is formed on an organic passivation film. The shielding transparent conductive film is connected to the earth pad through a conductor. Below organic passivation film of the terminal portion, a wire is formed.

CLAIM OF PRIORITY

The present application claims priority from Japanese Patent ApplicationNo. 2016-027838 filed on Feb. 17, 2016, the content of which is herebyincorporated by reference into this application.

BACKGROUND OF THE INVENTION (1) Filed of the Invention

The present invention relates to a display device, and more specificallyto a liquid crystal display device that decreases its outer size byreducing a terminal region.

(2) Description of the Related Art

A liquid crystal display device includes a thin film transistor (TFT)substrate and a counter substrate disposed opposed to the TFT substrate.The TFT substrate includes pixels each having a pixel electrode, a thinfilm transistor, and other elements in a matrix configuration. A liquidcrystal is sandwiched between the TFT substrate and the countersubstrate. Images are formed by controlling the light transmittance ofliquid crystal molecules in each pixel.

The liquid crystal display device has a problem of viewing angles. Thein-plane switching (IPS) mode is a method in which liquid crystalmolecules are rotated by an electric field in parallel with thesubstrate to change the transmittance of a liquid crystal layer, and themethod has excellent viewing angle characteristics. Basically in the IPSmode, it is unnecessary to form a counter electrode on the countersubstrate. Thus, this allows a simplified structure. However, externalnoise is easily entered from the counter substrate side.

In order to prevent external noise from being entered, a shieldingconductive layer (a shielding ITO) is formed on the outer surface of thecounter substrate. The configuration of the shielding ITO is describedin Japanese Patent Application Laid-Open No. 2011-123231, for example.Japanese Patent Application Laid-Open No. 2011-123231 describes aconfiguration in which a shielding ITO of a counter substrate isconnected to a pad formed on a TFT substrate using a resin.

The shielding ITO formed on the surface of the counter substrate has tobe connected to an earth or reference potential. For this connection, anearth pad is formed on the TFT substrate side, and the earth pad isconnected to the shielding ITO of the counter substrate using aconductive tape, for example. However, in order to maintain the adhesivestrength of the conductive tape, the earth pad needs a certain area. Thearea of the earth pad is an area of 3 mm×1.8 mm, for example.

The definition of the liquid crystal display device is higher, whichresults in providing a large number of wires as well. In order to formthese wires on a terminal portion, the terminal portion needs a certainarea. On the other hand, specifically in middle- or small-sized liquidcrystal display devices, it is demanded to decrease the outer size ofthe liquid crystal display panel. This also demands a smaller area ofthe terminal portion. However, the earth pad needs a predetermined area,and this imposes a limit on a decrease in the size of the liquid crystaldisplay panel.

An object of the present invention is to achieve a configuration thatallows a decrease in the area of the terminal portion with a necessaryarea of an earth pad being secured and the downsizing of a liquidcrystal display panel.

SUMMARY OF THE INVENTION

An object of the present invention is to solve the problems. Specificmain aspects are as follows.

(1) A liquid crystal display device including a TFT substrate and acounter substrate attached to the TFT substrate with a sealing materialand includes a display region and a terminal portion formed on the TFTsubstrate. A shielding transparent conductive film is formed on theouter side of the counter substrate. On the terminal portion, an earthpad formed with a transparent conductive film is formed on an organicpassivation film. The shielding transparent conductive film is connectedto the earth pad through a conductor. Below the organic passivation filmof the terminal portion, a wire is formed.

(2) A liquid crystal display device including a TFT substrate and acounter substrate attached to the TFT substrate with a sealing materialand includes a display region and a terminal portion formed on the TFTsubstrate. On the terminal portion, a first wire extending in a firstdirection and a second wire extending in second direction are present.At an intersecting part of the first wire with the second wire, thesecond wire is separated into a first portion and a second portion. Atthe intersecting part, an organic film is formed covering the first wireand the second wire. On the organic film, a transparent conductive filmis formed. The second wire is connected to the transparent conductivefilm through a through hole formed on the organic film. The firstportion is connected to the second portion through the transparentconductive film.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a liquid crystal display device to which anembodiment of the present invention is applied;

FIG. 2 is a cross sectional view of a pixel in a display region;

FIG. 3 is a cross sectional view of a portion near an earth padaccording to a first embodiment;

FIG. 4 is a plan view of a liquid crystal display device with noconductive tape;

FIG. 5 is a plan view of a portion near an earth pad;

FIG. 6 is a cross sectional view taken along line B-B in FIG. 5;

FIG. 7 is a plan view of a first form of a second embodiment;

FIG. 8 is a cross sectional view taken along line C-C in FIG. 7;

FIG. 9 is a cross sectional view take along line D-D in FIG. 7;

FIG. 10 is a plan view of a second form of the second embodiment;

FIG. 11 is a cross sectional view taken along line E-E in FIG. 10;

FIG. 12 is a plan view of a third form of the second embodiment;

FIG. 13 is a cross sectional view taken along line F-F in FIG. 12;

FIG. 14 is a cross sectional view taken along line G-G in FIG. 12; and

FIG. 15 is a cross sectional view of a fourth form of the secondembodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the following, the content of the present invention will be describedin detail using embodiments.

First Embodiment

FIG. 1 is a plan view of a liquid crystal display device to which anembodiment of the present invention is applied. FIG. 1 is a liquidcrystal display device for use in a mobile telephone, for example. InFIG. 1, on a TFT substrate 100, scanning lines 10 are arrayed in thevertical direction, which extend in the lateral direction. Picturesignal lines 20 are arrayed in the lateral direction, which extend inthe vertical direction. A region surrounded by the scanning lines 10 andthe picture signal lines 20 is a pixel 30.

In FIG. 1, the TFT substrate 100 is attached to a counter substrate 200with a sealing material 150. On the inner side of the sealing material150, a display region 400 is formed. The TFT substrate 100 is formedgreater than the counter substrate 200. A portion where only the TFTsubstrate 100 is provided is a terminal portion 160. On the terminalportion (the terminal region) 160, a driver IC 161 that drives a liquidcrystal display panel is disposed, to which a flexible circuit board 162is connected for supplying power and signals to the liquid crystaldisplay panel.

FIG. 1 is an IPS-mode liquid crystal display panel. On the surface ofthe counter substrate 200, a shielding conductive layer (a shieldingITO) is formed. In order to connect the shielding ITO to an earthpotential or a reference potential, an earth pad is formed on theterminal portion, and the earth pad is connected to the shielding ITO ofthe counter substrate using a conductive tape 170, for example.

The conductive tape 170 is in a configuration, for example, in which anadhesive material having fine conductive particles dispersed is formedon one face of a metal tape, such as an Al tape and a copper tape. Inother words, the conductive tape 170 is attached to the shielding ITOand the earth pad with the adhesive material. Thus, in order to maintainadhesive strength, the earth pad needs a predetermined area. Thepresence of the earth pad is a problem of decreasing the area of theterminal portion.

The shielding ITO can be connected to the earth pad using the conductivetape as well as using a conductive resin and metal paste, for example.However, also in this case, the earth pad similarly needs a certainarea. In the following, the description is made in which the shieldingITO is connected to the earth pad using the conductive tape. Theembodiment of the present invention is similarly applicable in the caseof using a conductive resin and metal paste, for example.

FIG. 2 is a cross sectional view of the pixel in the display region ofthe IPS-mode liquid crystal display device. There are a variety of theIPS mode display devices. For example, a present main stream method is amethod in which a common electrode is formed flatly, a comb-teeth pixelelectrode is disposed on the common electrode with an insulating filmbeing sandwiched, and liquid crystal molecules are rotated using anelectric field generated between the pixel electrode and the commonelectrode. The reason is because this method can relatively increase thetransmittance.

FIG. 2 is a cross sectional view of such an IPS-mode liquid crystaldisplay device. A TFT in FIG. 2 is a so-called top gate TFT. Asemiconductor to be used is low-temperature Poli-Si (LIPS). In contrast,in the case of using an amorphous silicon (a-Si) semiconductor, aso-called bottom gate TFT is often used. In the following description,the description will be made using an example of the case of using a topgate TFT. The embodiment of the present invention is also applicable inthe case of using a bottom gate TFT. Moreover, oxide is also usableinstead of silicon.

In FIG. 1, on the glass substrate 100, a first base film 101 made ofsilicon nitride (SiN) and a second base film 102 made of silicon oxide(SiO₂) are formed by chemical vapor deposition (CVD). The first basefilm 101 and the second base film 102 are responsible for preventing asemiconductor layer 103 from being contaminated by impurities from theglass substrate 100.

On the second base film 102, the semiconductor layer 103 is formed. Thesemiconductor layer 103 is a layer made of a poly-Si film, in which ana-Si film is formed on the second base film 102 by CVD and islaser-annealed and converted into the poly-Si film. The poly-Si film ispatterned by photolithography.

On the semiconductor film 103, a gate insulating film 104 is formed. Thegate insulating film 104 is an SiO₂ film made of tetraethoxysilane(TEOS). This film is also formed by CVD. On the gate insulating film104, a gate electrode 105 is formed. The scanning line 10 also functionsas the gate electrode 105. The gate electrode 105 is formed of an Moalloy e.g. an MoW film. When it is necessary to decrease the resistanceof the gate electrode 105 or the scanning line 10, a stack of an Alalloy or Al alloy and an Mo alloy is used.

After that, an interlayer insulating film 106 is formed of SiO₂, whichcovers the gate electrode 105. The interlayer insulating film 106 isprovided for insulating the scanning line 10 from the picture signalline 20 or for insulating the gate electrode 105 from the contactelectrode 107. On the interlayer insulating film 106 and the gateinsulating film 104, a contact hole 120 is formed for connecting thesemiconductor layer 103 to a contact electrode 107.

On the interlayer insulating film 106, the contact electrode 107 isformed. The semiconductor layer 103 is connected to the picture signalline 20 through the contact hole at a portion not shown.

The contact electrode 107 and the picture signal line 20 aresimultaneously formed on the same layer. In order to decrease theresistance of the contact electrode 107 and the picture signal line 20,an Al alloy e.g. AlSi alloy is used. Since the AlSi alloy causeshillocks, or defuses its Al to other layers, a structure is provided, inwhich the AlSi alloy layer is sandwiched between an MoW barrier layerand a cap layer, for example. However, in the specification, aconfiguration is also simply referred to as an Al alloy wire.

An organic passivation film (an organic film) 108 is formed covering thepicture signal line 20 or the contact electrode 107. The organicpassivation film 108 is formed of a photosensitive acrylic resin. Inaddition to acrylic resins, the organic passivation film 108 can also beformed of a silicone resin, epoxy resin, polyimide resin, and otherresins. Since the organic passivation film 108 functions as aplanarization film, this film is formed thickly. In many cases, the filmthickness of the organic passivation film 109 is in a range of 2 to 4μm. In the embodiment, the film thickness is in a range of about 3 to 4μm.

As described later, in the embodiment of the present invention, theorganic passivation film 108 is left on a part of the terminal portion160, and an earth pad formed of a conductive film, such as indium tinoxide (ITO), is formed on the organic passivation film 108. Thus, thisallows wires to be formed also on the lower side of the earth pad, andthe area of the terminal portion 160 is decreased.

In order to conduct the continuity between the pixel electrode 112 andthe contact electrode 107, a contact hole 130 is formed on the organicpassivation film 108. A photosensitive resin is used for the organicpassivation film 108. After coating a photosensitive resin, this resinis exposed, and then only portions to which light is applied aredissolved in a specific developer. In other words, forming a photoresistcan be omitted using a photosensitive resin. After forming the contacthole 130 on the organic passivation film 108, the organic passivationfilm is baked at a temperature of about 230° C., and thus the organicpassivation film 108 is finally formed. In this baking, an earth padorganic passivation film 108 to be formed on the terminal portion 160 isalso simultaneously formed.

After baking, ITO to be the common electrode 109 is formed bysputtering, and then patterned so as to remove the ITO from the contacthole 130 and the portions around the contact hole 130. The commonelectrode 109 can be flatly formed common in the pixels. ITO has a largeresistivity. Thus, in order to prevent a voltage drop in the commonelectrode 109, a common metal wire 110 is formed being overlapped withthe common electrode 109. In order to prevent the transmittance of thepixel from being dropped, the common metal wire 110 is formed on aportion overlapped with the picture signal line 20 or the scanning line10 in a planner view.

After that, SiN to be a capacitive insulating film 111 is formed onthroughout the surface by CVD. Since the capacitive insulating film 111is also responsible for forming the retention capacitance between thepixel electrode 112 and the common electrode 109, the capacitiveinsulating film 111 has this name. After that, in the contact hole 130,a contact hole for conducting the continuity between the contactelectrode 107 and a pixel electrode 112 is formed on the capacitiveinsulating film 111.

After that, ITO is formed by sputtering, and patterned to form the pixelelectrode 112. On the pixel electrode 112, an alignment film material isapplied by flexographic printing, ink jet, and other methods, and thenbaked to form an alignment film 113. For the alignment process of thealignment film 113, photo-alignment using polarized ultraviolet rays isused in addition to rubbing.

When a voltage is applied across the pixel electrode 112 and the commonelectrode 110, electric flux lines as illustrated in FIG. 2 aregenerated. Liquid crystal molecules 301 are rotated by these electricfields, and the amount of light transmitted through the liquid crystallayer 300 is controlled for each pixel. Thus, images are formed.

In FIG. 2, the counter substrate 200 is disposed with the liquid crystallayer 300 being sandwiched. On the inner side of the counter substrate200, a color filter 201 is formed. On the color filter 201, red, green,and blue color filters are individually formed on the pixels. Thus,color images are formed. A black matrix 202 is formed between the colorfilters 201 for improving the contrast of images. Note that, the blackmatrix 202 is also responsible for the light shielding film of the TFT,and prevents a photocurrent from being carried through the TFT.

An overcoat film 203 is formed covering the color filter 201 and theblack matrix 202. The overcoat film 203 is provided for preventing thematerial of the color filter 201 from being dissolved into the liquidcrystal layer 300. On the overcoat film 203, an alignment film 113 thatdetermines the initial alignment of the liquid crystal molecules isformed. Similarly to the alignment film 113 on the TFT substrate 100side, rubbing or photo-alignment is used for the alignment process ofthe alignment film 113.

As described above, in the IPS mode, it is unnecessary to form thecounter electrode on the counter substrate. When the configuration asillustrated in FIG. 2 is formed, it is difficult to shield noise fromthe counter substrate side. Therefore, a shielding ITO 210 is formed onthe surface of the counter substrate for shielding external noise. Thethickness of the shielding ITO 210 is in a range of about 200 to 300 nm.However, in order to shield noise, the shielding ITO 210 has to beconnected to an earth or a reference potential (in the following,referred to as an earth).

The conductive tape 170 in FIG. 1 is provided for connecting theshielding ITO 210 to the earth pad to be the earth potential. FIG. 3 isa cross sectional view taken along line A-A in FIG. 1, illustrating across sectional view of the portion of the earth pad. In FIG. 3, the TFTsubstrate 100 is attached to the counter substrate 200 with the sealingmaterial 150. The liquid crystal 300 is sandwiched between the TFTsubstrate 100 and the counter substrate 200. At the end portion of thecounter substrate 200, a wall-like spacer 250 is formed, not the sealingmaterial 150. The wall-like spacer 250 is provided for removing a partof the counter substrate 200 from the terminal side by scribing.

In FIG. 3, as the layers on the TFT substrate 100 side, only the organicpassivation film 108 is illustrated. A groove 1081 is formed on the partof the organic passivation film 108 overlapped with the sealing material150. The groove 1081 is provided for preventing external moisture frombeing entered through the organic passivation film 108.

The embodiment of the present invention is characterized in that in theterminal portion 160, the organic passivation film 108 extends to theportion on which the earth pad 70 is formed. A transparent conductivefilm 80, such as connection ITO, is formed on the organic passivationfilm 10, and thus the earth pad 70 is formed. With this configuration,the region below the earth pad 70 can also be used as the wire region,which allows the area of the terminal portion to be decreased by thisregion.

The earth pad 70 is connected to the shielding ITO 210 of the countersubstrate 200 with the conductive tape 170. Note that, the connectionITO (the connection conductive film) 80 of the earth pad 70 can beconnected to a terminal provided on the end portion of the TFT substratethrough a wire separately provided. In FIG. 3, the organic passivationfilm 108 is formed continuously to the organic passivation film 108 ofthe display region 400. However, a configuration may be possible, inwhich the organic passivation film 108 of the display region 400 isisolated from the organic passivation film 108 of the terminal portion160 and the organic passivation film 108 of the terminal portion 160 isformed in an island shape. With this configuration, moisture can beprevented from being entered to the organic passivation film 108 of thedisplay region 400 through the organic passivation film 108 of theterminal portion 160.

FIG. 4 is a plan view of the liquid crystal display panel before theshielding ITO 210 is connected to the earth pad 70 with the conductivetape 170. In the terminal portion 160 in FIG. 4, the earth pad 70 isformed on the portion adjacent to the counter substrate 200. The earthpad 70 is configured of the organic passivation film 108 and theconnection ITO 80 formed on the organic passivation film 108. The otherconfigurations are similar to ones described in FIG. 1.

FIG. 5 is a plan view of the portion near the earth pad 70 in FIG. 4. InFIG. 5, the earth pad 70 is formed adjacent to the counter substrate200. The earth pad 70 is a component having the connection ITO 80 formedon the organic passivation film 108. Below the organic passivation film108, various wires are formed. Wires in wide width in FIG. 5 are wireregions. In these regions, a large number of narrow lead wires of thepicture signal lines 20 may be formed.

FIG. 6 is a cross sectional view taken along line B-B in FIG. 5. In FIG.6, a lead wire 40 is formed of a stack of a lead wire made of an Moalloy 42 formed on the same layer as the scanning line 10 and a leadwire made of an Al alloy 41 formed on the same layer as the picturesignal line 20. The lead wire 41 is formed of an Al alloy, for example.The lead wire 42 is formed of an Mo alloy, for example. In FIG. 6, theorganic passivation film 108 is formed covering the lead wire 40, andthe connection ITO 80 is formed on the organic passivation film 108. Theearth pad 70 is formed of the connection ITO 80 and the organicpassivation film 108.

The connection ITO 80 is formed of a first connection ITO 81simultaneously formed with the common electrode 109 and a secondconnection ITO 82 simultaneously formed with the pixel electrode 112.The connection ITO 80 may be formed of only any one of the firstconnection ITO 81 and the second connection ITO 82. However, both of thecommon electrode 109 and the pixel electrode 112 are as thin as athickness of 100 nm or less, and thus a two-layer structure is providedto improve reliability.

In FIG. 6, the terminal end portion of the organic passivation film 108is covered with the capacitive insulating film 11 formed of SiN. This isbecause moisture is prevented from being entered to the organicpassivation film 108. The lead wire 41 formed of Al is absent at theterminal end portion of the organic passivation film 108. This isbecause in patterning the first connection ITO 81, a risk of a shortcircuit between the lead wires 40 is eliminated, which is caused by theresidue of the first connection ITO 81.

In other words, at the terminal end portion of the organic passivationfilm 108 in FIG. 6, the interlayer insulating film 106 is formed. At theterminal end portion of the organic passivation film 108, the lead wire40 is connected only with the Mo alloy 42 formed on the same layer asthe scanning line 10. However, at the portion beyond the terminal endportion of the organic passivation film 108, the lead wire 40 is againin the two-layer configuration of the Al alloy 41 and the Mo alloy 42.Therefore, there is almost no increase in the resistance of the leadwire 40.

In FIG. 6, the lead wire made of the Mo alloy 42 is formed on the gateinsulating film 104. In FIG. 6, the first base film 101 and the secondbase film 102 are omitted. Finally, the conductive tape 170 is connectedto the connection ITO 80, and the earth pad 70 is connected to theshielding ITO 210.

As described above, the wires, such as the lead wire 400, can also beformed below the earth pad 70. Thus, the area of the terminal portioncan be decreased. The organic passivation film 108 of the terminalportion 160 can be simultaneously formed with the organic passivationfilm 108 on the display region 400. Consequently, processing loads arenot increased.

Second Embodiment

The configuration in which the area of the terminal portion is decreasedusing the organic passivation film and the connection ITO described inthe first embodiment is also applicable to the portions other than theterminal portion. FIG. 7 is a diagram of an example of decreasing thearea of the terminal portion in which a lead wire made of an Al alloy 41is three dimensionally crossed with an inspection wire 50, which areformed on a terminal portion 160, using an organic passivation film 103.

In FIG. 7, on the inspection wire 50 extending in the lateral direction,the organic passivation film 108 is formed in an island shape, and aconnection ITO 80 is formed on the organic passivation film 108. Asignal line 40 extends in the vertical direction. The signal line 40 canbe three dimensionally crossed with the inspection wire 50 using theorganic passivation film 108. The inspection wire 50 and the signal line40 in FIG. 7 are both formed of the Al alloy 41 formed on the same layeras the picture signal line. The connection ITO 80 in FIG. 7 functions asa bridge between the signal lines 40 formed above and below the organicpassivation film 108.

FIG. 8 is a cross sectional view taken along line C-C in FIG. 7. In FIG.8, the inspection wire 50 formed of the Al alloy 41 extends on a gateinsulating film 104 and an interlayer insulating film 106 in the lateraldirection. On the inspection wire 50, the organic passivation film 108is formed. On the organic passivation film 108, the connection ITO 80 isformed. The connection ITO 80 has a two-layer structure of a firstconnection ITO 81 and a second connection ITO 82. The reason why thisstructure is provided is similar to the reason described in FIG. 6. Onthe end portion of the organic passivation film 108 and the Al alloy 41uncovered with the organic passivation film 108, a capacitive insulatingfilm 111 formed of SiN is formed. The capacitive insulating film 111 isformed for preventing the Al alloy 41 from corroding.

FIG. 9 is a cross sectional view taken along line D-D in FIG. 7 D-D,illustrating a cross sectional view of a through hole 60 for connectingthe signal line 40 to the connection ITO 80. In FIG. 9, on the gateinsulating film 104 and the interlayer insulating film 106, the leadwire 40, such as a common wire formed of the Al alloy 41, is formed. Thelead wire 40 is covered with the organic passivation film 108, andconnected to the connection ITO through the through hole 60 formed onthe organic passivation film 108. The connection ITO 80 has aconfiguration of a stack of the first connection ITO 81 and the secondconnection ITO 82.

As described in FIGS. 7 to 9, the lead wire 40 and the inspection wire50 can be formed being overlapped with each other by forming the organicpassivation film 108. Thus, the wiring area of the terminal portion canbe made smaller. This configuration specifically exerts effects wireswith wide width, such as a common wire, specifically.

The connection ITO 80 used for the bridge has a large resistivity, whichsometimes causes a problem of wire resistance. FIGS. 10 and 11 arediagrams of a second form of the embodiment, illustrating aconfiguration for decreasing the wire resistance of the bridge by astack of the common metal wire 110 and the connection ITO 80.

In FIG. 10, the inspection wire 50 formed of the Al alloy 41 extends inthe lateral direction, and the organic passivation film 108 is formedcovering the inspection wire 50. The signal lead wire 40 formed of theAl alloy 41 extends in the vertical direction, and bridged by theconnection ITO 80 formed on the organic passivation film 108, which issimilar to the configuration described in FIGS. 7 to 9.

In FIG. 10, the common metal wire 110 is formed being overlapped withthe connection ITO 80 on both sides. The common metal wire 110 is formedof an Al alloy, for example, and thus the resistance of the bridgeportion can be greatly decreased. A cross section taken along line D-Din FIG. 10, which is a cross section of the through hole 60, is similarto FIG. 9. Note that, the cross section of the through hole, on whichthe common metal wire 110 is formed, is in a configuration in which thecommon metal wire 110 is formed between the first connection ITO 81 andthe second connection ITO 82 in FIG. 9.

FIG. 11 is a cross sectional view taken along line E-E in FIG. 10. InFIG. 11, on the gate insulating film 104 and the interlayer insulatingfilm 106, the inspection wire 50 formed of the Al alloy 41 extends inthe lateral direction. The organic passivation film 108 is formed in anisland shape covering the inspection wire 50. On the organic passivationfilm 108, the first connection ITO 81 is formed, and the common metalwire 110 is stacked on both sides of the first connection ITO 81. Thecommon metal wire 110 is also formed of the Al alloy 41. The secondconnection ITO 82 is formed covering the first connection ITO 81 and thecommon metal wire 110. The capacitive insulating film 111 formed of SiNis formed covering the side of the organic passivation film 108 and theinspection wire 50.

As illustrated in FIG. 11, the common metal wire 110 is stacked on thefirst connection ITO 81, and thus the resistance of the bridge wire canbe greatly decreased. Note that, in FIG. 11, the common metal wire 110is formed on the first connection ITO 81. However, the common metal wire110 is sometimes formed below the first connection ITO 81. The effect isthe same. In any cases, the order of processes for the display regionhas to be followed.

FIGS. 12 to 14 are diagrams of a third form of the embodiment,illustrating another configuration for decreasing the resistance of thebridge connection formed on the island-shaped portion of the organicpassivation film 108. The configuration of FIG. 12 is different from theconfiguration of FIG. 10 in that in order to decrease the resistance ofthe bridge connection, the Mo alloy 42 is used, which is formed on thelower side of the Al alloy 41 and formed on the same layer as thescanning line 10.

FIG. 13 is a cross sectional view taken along line F-F in FIG. 12. InFIG. 13, the bridge wire formed of the Mo alloy 42 is formed on the gateinsulating film 104. On the interlayer insulating film 106 formed on theMo alloy 42, the inspection wire 50 formed of the Al alloy 41 extends inthe lateral direction. The organic passivation film 108 is formed in anisland shape on the inspection wire 50. The first connection ITO 81 andthe second connection ITO 82 are formed on the organic passivation film108.

FIG. 14 is a cross sectional view taken along line G-G in FIG. 12,illustrating the cross section of a through hole 65 in the third form.In FIG. 14, the Mo alloy 42 used as a bridge electrode is formed on thegate insulating film 104. On the Mo alloy 42, the interlayer insulatingfilm is formed. On the interlayer insulating film 106, the Al alloy 41for the wire 40 is formed. The Mo alloy 42 is connected to the Al alloy11 through the through hole 65. The organic passivation film 103 isformed covering the lead wire 40 formed of the Al alloy 41. On theorganic passivation film 108, a stack of the first connection ITO 81 andthe second connection ITO 82, which is the bridge wire, is formed.

As described above, in the third form, the connection ITO 80 is formedon the upper side of the inspection wire with the organic passivationfilm 108 being sandwiched, and the electrode formed of the Mo alloy 42is formed on the lower side of the inspection wire 50 with theinterlayer insulating film 106 being sandwiched. Thus, the resistance ofthe bridge portion is decreased.

In the description above, the description is made in which the wire ofthe lower layer configuring the scanning line is formed of the Mo alloy,for example, and the wire of the upper layer configuring the picturesignal line is formed of the Al alloy. However, the embodiment of thepresent invention is not limited to this configuration. The embodimentof the present invention is also applicable to the case in which thelower layer is formed of an Al alloy and the upper layer is formed of anMo alloy. Moreover, the embodiment of the present invention is alsoapplicable to the case in which both of the upper layer and the lowerlayer are formed of an Al alloy and to the case in which both of theupper Layer and the lower layer are formed of an Mo alloy.

One of problems in the case in which wires are three dimensionallycrossed with each other is a stray capacitance formed between the lowerlayer wire and the upper layer wire. In the embodiment of the presentinvention, the organic passivation film is used in the terminal portion.Thus, this allows a large gap to be provided between the lower layerwire and the upper layer wire, allowing a stray capacitance to bedecreased. In the embodiment of the present invention, the thickness ofthe organic passivation film is in a range of 2 to 4 μm, and morepreferably in a range of 3 to 4 μm.

In the description above, the description is made using an example inwhich the pad electrode or the bridge electrode formed on the organicpassivation film is made of ITO. This is an example in the case in whichthe transparent conductive film to be used as the pixel electrode or thecommon electrode is formed of ITO. In the case in which the pixelelectrode or the common electrode is formed of another transparentconductive film, which is formed of AZO and IZO, for example, the padelectrode or the bridge electrode can be formed of a material the sameas these materials.

In the second embodiment, the description is made using an example ofthe configuration in which the signal wire in the terminal portion isthree dimensionally crossed with the inspection wire through the organicpassivation film. However, the wire of the lower layer is not limited tothe inspection wire, which may be any wires. A configuration may bepossible in which the lower layer is provided for a certain signal wireand the inspection wire is three dimensionally crossed with this signalwire through the organic passivation film. In any cases, a configurationmay be possible in which the bridge electrode is used as a terminal,such as a bridge electrode to be contacted with an inspection probe. Inthe embodiments above, the organic passivation film is formed in anisland shape, which is matched with the shape of the connection ITO 80.A configuration may be possible as in FIG. 15 in which the organicpassivation film is formed in a wide, flat shape, not formed in anisland shape. Similarly, also in FIGS. 11 and 13, a configuration may bepossible in which the organic passivation film is formed in a fiatshape, not formed in an island shape. The same thing is applied to theembodiment in FIG. 6. In this case, the Al alloy 41 of the lead wire 40does not have to be separated at the end portion of the organicpassivation film unlike the configuration in FIG. 6. Conversely, in thecase in which the organic passivation film is provided in an islandshape in any parts not limited to the pad portion and a wire is providedbelow the organic passivation film, in order to prevent a short circuitbetween wires caused by the transparent conductive film, the interlayerinsulating film 106 preferably provided between the organic passivationfilm and the wire below the organic passivation film at the end portionof the organic passivation film.

The embodiments of the present invention are suitable for the IPS-modeliquid crystal display device because the embodiments of the presentinvention can be implemented with no increase in processing loads.However, the embodiments of the present invention are also applicable toliquid crystal display devices in other modes, including twisted nematic(TN) and vertical alignment (VA) liquid crystal display devices, forexample. The embodiments of the present invention are generallyapplicable to display devices, such as organic electroluminescentdisplay devices, in addition to liquid crystal display devices.

What is claimed is:
 1. A display device comprising: a first substratehaving a first transparent conductive film; a second substrate having afirst region, a second region, an organic passivation film, a secondtransparent conductive film, and a lead wire at the second region; asealing material which attaches the first substrate and the secondsubstrate; a conductor, wherein the first region overlaps the firstsubstrate, the second region does not overlap the first substrate, theorganic passivation film has a first portion and a second portion, thefirst portion is located at the first region; the first portion and thesecond portion are isolated by a groove formed in the organicpassivation film, the sealing material overlaps the groove, the secondtransparent conductive film is provided on the second portion at thesecond region, the first transparent conductive film is connected to thesecond transparent conductive film by the conductor, the lead wireoverlaps the second transparent conductive film and the second portion,and the lead wire is not connected to the second transparent conductivefilm.
 2. The display device of claim 1, wherein the first portion of theorganic passivation film is a planarization portion, and the secondportion of the organic passivation film is an island portion.
 3. Thedisplay device of claim 2, wherein the second substrate further includesa glass substrate, the island portion is between the glass substrate andthe second transparent conductive film, the lead wire is between theglass substrate and the island portion.
 4. The display device of claim3, wherein the lead wire has a first metal layer and a second metallayer stacked on the first metal layer.
 5. The display device of claim4, wherein the second substrate further has an interlayer insulatingfilm and an inorganic insulating film, the island portion has an endportion which defines an island shape of the island portion, the endportion is covered by the inorganic insulating film, the interlayerinsulating film is in contact with the inorganic insulating film outsideof the end portion.
 6. The display device of claim 5, wherein the secondmetal layer is separated by a gap, the interlayer insulating film isprovided on the first metal layer at the gap between the first metal andthe second metal.
 7. The display device of claim 2, wherein the islandportion has an end portion which defines an island shape of the islandportion, the lead wire crosses the end portion.
 8. The display device ofclaim 2, wherein the island portion has a first end portion and a secondend portion, which defines an outer shape of the island portion, thelead wire crosses the first end portion and a second end portion.
 9. Thedisplay device of claim 1, further comprising a wall-like spacer,wherein the wall-like spacer overlaps the second portion, the wall-likespacer is located between the sealing material and a border between thefirst region and the second region.